Hooks can no longer change calls to the account memory server

Hooks are your own scripts or functions that Claude Code runs around its actions, for example just before a tool runs. The account memory server is an MCP server that holds memory tied to your account. An MCP server is a connector that gives Claude extra tools.

Hooks can still allow or deny a call to the account memory server, but they can no longer change it:

• PreToolUse, PermissionRequest, managed-policy and function hooks that return changed input get the call denied and a warning logged. An empty change on the PermissionRequest path is still accepted.
• A managed PostToolUse hook that rewrites the server's output has the rewrite dropped. The original output goes to the model.
• A plugin hooks module that answers the call in place of the real server has its answer dropped. If the server gave no result, the call is refused.

Output rewrites for every other tool still apply.